I do like frontal area and mass to drop a bear handily. The 33 calibres and up seem to work very well on bear. I've taken more bears with 35 calibres of various iterations than with any other calibre. They have generally worked quite well for me. However, even 28 calibre and less will work if the angle is correct and the shot is placed where it belongs.

375 without a doubt for me. even in a light gun the recoil is very manageable. i own a 470 double and a 416 double a few 458 bolts actions and i done even bring them anymore instead i use my 375 for anything big and a 30 cal for Long Range plains game. i used to bring the doubles when you could still bring 3 guns but now that its mostly 2 guns (most versitle setup to cover everything this has become my setup and i have shot up to and including elephant DRT with the 375. just get 2 loads solids and softs that shoot to the same POI and youre set, and only use the solids for the really big stuff. have half a dozen buff all one shot kills etc its a great round and operator friendly. i am not knocking the other stuff out there but many people cant handle the higher recoiling rounds as well as they think they can and i rather be able to shoot where i want than shoot a more powerful gun.

If the shots are further or the climb is steep and/or rough I'll take my custom Model 70 in 338wm.

If it's thick or I'm going in to the thick to find a wounded bear I like my 416 Rigby with 400 grain Swift AFrames.

I've killed a number of bears with each and they both work very well.

Last spring one of our bear hunting group brought his son on his first bear hunt. We spotted a nice big black bear boar for him and he got the fever during the stalk and just pissed it off. He ran into the thickest crap you don't want to go into with a hole in his rear leg. My partner and I went in and I finished him off at about 25 feet as he started to come for us. I double lunged him with the 416. He kinda looked like he got pushed over hard and didn't really move again.

I have never hunted the big bears but have hunted cape buffalo and lion in Africa. The 375 H&H is very effective when there is some distance between you and an unaware animal. Also, an excellent choice when you have the opportunity to take other species that could present longer shots. Trajectories are similar to a 180gr. 30-06. It's very manageable and easy to shoot well. In close quarters and thick cover, particularly if the animal is aware of your presence, it's the 450 H&H double.